feat: add sqlite telemetry with single-emitter discipline

src/polygateway/telemetry/sqlite.py

@@ -0,0 +1,93 @@
+"""SQLite 遥测后端(默认): WAL + 单持久连接 + to_thread 桥接。
+
+蓝本 VT `adapters/telemetry.py`: 构造期建连接与表,失败降级为 no-op
+(记录基础设施不得拖垮业务调用);`INSERT OR IGNORE` 幂等(call_id 主键);
+写入经 threading.Lock 串行化后由 `asyncio.to_thread` 执行,不阻塞事件循环。
+"""
+
+from __future__ import annotations
+
+import asyncio
+import sqlite3
+import threading
+from pathlib import Path
+
+from loguru import logger
+
+_DDL = """
+CREATE TABLE IF NOT EXISTS llm_calls (
+    call_id            TEXT PRIMARY KEY,
+    parent_call_id     TEXT,
+    session_id         TEXT,
+    model              TEXT    NOT NULL,
+    provider           TEXT    NOT NULL,
+    source_name        TEXT    NOT NULL,
+    messages           TEXT    NOT NULL,
+    response           TEXT    NOT NULL,
+    thinking           TEXT    NOT NULL DEFAULT '',
+    prompt_tokens      INTEGER NOT NULL,
+    completion_tokens  INTEGER NOT NULL,
+    usage_source       TEXT    NOT NULL,
+    latency_ms         INTEGER NOT NULL,
+    ttft_ms            REAL,
+    max_inter_token_ms REAL,
+    cache_hit          INTEGER NOT NULL DEFAULT 0,
+    error              TEXT,
+    cost               REAL,
+    created_at         TEXT    NOT NULL DEFAULT (datetime('now'))
+);
+"""
+
+_COLUMNS = (
+    "call_id", "parent_call_id", "session_id", "model", "provider", "source_name",
+    "messages", "response", "thinking", "prompt_tokens", "completion_tokens",
+    "usage_source", "latency_ms", "ttft_ms", "max_inter_token_ms", "cache_hit",
+    "error", "cost",
+)
+
+_INSERT = (
+    f"INSERT OR IGNORE INTO llm_calls ({', '.join(_COLUMNS)}) "
+    f"VALUES ({', '.join('?' for _ in _COLUMNS)})"
+)
+
+
+class SQLiteRecorder:
+    """TelemetryRecorder 端口的 SQLite 实现;初始化/写入失败全降级 warning。"""
+
+    def __init__(self, db_path: Path | str) -> None:
+        self._lock = threading.Lock()
+        self._conn: sqlite3.Connection | None = None
+        try:
+            path = Path(db_path)
+            path.parent.mkdir(parents=True, exist_ok=True)
+            conn = sqlite3.connect(path, check_same_thread=False, timeout=10.0)
+            conn.execute("PRAGMA journal_mode=WAL")
+            conn.execute("PRAGMA busy_timeout=5000")
+            conn.execute(_DDL)
+            conn.commit()
+            self._conn = conn
+        except (OSError, sqlite3.Error) as exc:
+            logger.warning("SQLite 遥测初始化失败,后续记录降级为 no-op: {}", exc)
+
+    async def record_llm_call(self, **fields: object) -> None:
+        """写一行遥测;字段集合即 18 字段冻结签名(ports.TelemetryRecorder)。"""
+        if self._conn is None:
+            return
+        row = tuple(fields[col] for col in _COLUMNS)
+        try:
+            await asyncio.to_thread(self._write, row)
+        except (OSError, sqlite3.Error) as exc:
+            logger.warning("SQLite 遥测写入失败(降级不冒泡): {}", exc)
+
+    def _write(self, row: tuple) -> None:
+        assert self._conn is not None  # 内部不变量: 调用方已判空
+        with self._lock:
+            self._conn.execute(_INSERT, row)
+            self._conn.commit()
+
+    def close(self) -> None:
+        """幂等关闭持久连接。"""
+        conn, self._conn = self._conn, None
+        if conn is not None:
+            with self._lock:
+                conn.close()